Method and apparatus for producing fibers from mineral materials



NOV- 15, 1935 E. T. LINCOLN r-:TAL 3,218,139

METHOD AND APPARATUS FOR PRQDUCING FIBERS FROM MINERAL MATERIALS FlledJan. 16. 1961 2 Sheets-Sheet l ww @Y mi INVENTORS [pm/N0 7.' L /NcoL/v &By JAMfs M. [Rv/N v f mm/Law ATTORNEYS NOV. 16, 1965 E. T. LINCOLN ETAL3,218,139

METHOD AND APPARATUS FOR PRODUCING FIBERS FROM MINERAL MATERIALS 2Sheets-Sheet 2 Filed Jan. 16. 1961 Moa N 2 ma m9 Mmm m AF. l/ E M T. n0M o T M500 T Mm A A D EM/ Y l B i,

United States Patent O 3,218,139 METHOD AND APPARATUS FR PRGDUCINGFIBERS FROM NUNERAL MAT ERlALS Edmund T. Lincoln and .lames M. Ervin,San Jose, Calif.,

assignors to Owens-Corning Fiberglas Corporation, a

corporation of Delaware Filed Jan. 16, 1961, Ser. No. 83,042 Claims.(Cl. 65-5) This invention relates to method and apparatus for formingfibers from mineral materials by engaging high temperature, highvelocity gaseous blasts with primary filaments or rods of glass or othermineral material wherein the blasts soften the filaments or rods andattenuate the softened material to fibers and is inclusive of a methodand means of controlling the direction and flow of blastinduced air.

Glass fibers have been produced by attenuation through the utilizationof several comparatively large internal combustion burners disposed intransverse aligned relationship and in which combustible mixtures areburned and the products of combustion projected through restrictedelongated orifices providing intensely hot blasts into which aredelivered primary filaments of fusible mineral material, such as glass,and the primary filaments continuously advanced into the blasts, theheat of the gases of the blasts softening the filaments and the velocityof the blasts attenuating the filaments into fine fibers.

The fibers are delivered onto a moving conveyor and form a mat ofdesired character and of a thickness dependent upon the rate ofadvancement of the conveyor and the amount of glass attenuated by theblasts per unit of time. The blast producing burners have been arrangedin transverse alignment in an elongated open ended chamber and theattenuating blasts directed lengthwise of the chamber. The high velocityblasts induce movement of air along the blasts. Heretofore this methodof attenuation has been carried on without effective control of the airambient the blasts and air turbulence along the blast occurs which,under certain operating conditions, reduces or impairs the efficiency ofattenuation. Furthermore substantial turbulence fosters the tendency ofthe fibers to adhere to the interior surfaces of the chamber wallsrequiring frequent interruption of the process to remove the fibers fromthe walls.

The present invention embraces a method of restricting and controllingthe admission of air to the region of the blast whereby more smooth fiowof air along the blasts is achieved with a reduction in turbulencewhereby the efficiency of attenuation is greatly improved.

An object of the invention embraces a method of controlling anddirecting air admitted to fiber-attenuating gaseous blasts in a mannerwhereby an increased yield of fine fibers is obtained Without anyincrease in eX- pended energy.

Another object of the invention resides in an apparatus for channelingor directing air admitted to the gaseous blasts wherein the exit of thechanneling means is adjustable relative to the blasts to obtain thehighest efficiency of attenuation in the formation of fine fibers fromglass or other heat-softenable mineral material.

Another object of the invention resides in the provision of a walledfiber-collecting chamber of substantially greater Width than heretoforeemployed in comparison with the transverse dimension of a movingconveyor upon which the fibers are collected whereby a rnat of moreuniform thickness throughout the area of the conveyor is obtained andwherein there is a substantial reduction in the rate of accumulation offibers in regions adjacent each side of the conveyor.

Another object of the invention resides in the provi- ICC sion of anadjustable air conveying duct for delivering air to the attenuatingblasts in combination with a transverse wall disposed in a fibercollecting chamber whereby to provide a more efficient and effectivecontrol of the air admitted to the blasts effectively reducingturbulence in the chamber and thereby increasing the efiiciency ofattenuation and promoting increased ber yield.

Further objects and advantages are within the scope of this inventionsuch as relate to the arrangement, operation and function Of the relatedelements of the structure, to various details of construction and tocombination of parts, elements per se, and to economies of manufactureand numerous other features as will be apparent from a consideration ofthe specification and drawing of a form of the invention, which may bepreferred, in which:

FIGURE l is a longitudinal sectional view illustrating an apparatus forcarrying out the method of the invention in the production of glassfibers from streams of material delivered from a stream feeder, and

FIGURE 2 is a transverse sectional view taken substantially on the line2-2 of FIGURE l.

While the airv control apparatus for carrying out the method isexemplified as particularly useful with fiberattenuating blasts employedfor forming fibers from glass and continuously collecting the fibersinto mat formation, it is to be understood that the method of andapparatus for controlling blast-induced air may be employed in otherarrangements or facilities for producing attenuating blasts wherever thesame may be found to have utility.

Referring to the drawings in detail, the embodiment of the apparatusdisclosed is inclusive of an elongated walled fiber-forming andcollecting hood or chamber 10 defined by a ceiling 12, side walls 14 and16 and a floor or bottom wall 18 which includes a pit or recess 20.Arranged transversely of the chamber 10 is a wall or partition 22.Disposed adjacent and rearwardly of the transverse wall 22 is aplurality of means 26 from which are projected high velocity gaseousblasts 28. In the embodiment illustrated, the blast producing means 26,comprises a plurality of internal combustion burners arranged intransversely aligned relation as shown in FIGURE 2.

Each burner 26 is of a comparatively large size and is formed with aninternal combustion chamber or zone 27, combustible mixture beingsupplied to each burner under comparatively low pressure through asupply duct or pipe 30. The combustible `mixture is substantiallycompletely burned within the combustion chambers 27 of the burners andthe gases projected therefrom through transversely elongated restrictedorifices 34 provided in the front walls of the burners in directionsabove and lengthwise of the chamber or hood 10.

Means is provided for delivering bodies of fiberforming mineral materialinto the blasts for attenuation to fibers by the forces of the blasts.In the embodiment illustrated, a melting and refining furnace 38 issupported above the chamber 10 in which fiber-forming mineral material,such as glass batch, is reduced to a heat-softened fiowable condition. Asupply of the glass batch is contained in a hopper 40 and delivered intothe melting furnace 38 through a feeding device 42 actuated by a motor44 or other suitable means.

The material feeding means is controlled by conventional means todeliver raw batch into the furnace 38 at a rate at which theheat-softened glass is delivered from the furnace. The side walls of thefurnace 38 are provided with a plurality of burners or heating means 46for directing heat onto the glass batch to reduce the same to a moltenor flowable condition. A Weir or skimmer block 48 extends transverselyof the furnace in the refining region thereof and is spaced from thebottom wall anis,

f., FJ of the furnace to provide a passage Sil accommodating the flow ofthe glass from the furnace to a flow channel.

Connected with the forward end of the furnace is a neck 53 providing awalled flow channel del, the flow channel Se being disposed lengthwiseof the furnace and is connected with a forehearth construction 56extending transversely of the flow channel S4. The forehearth So isprovided with feeders bil, each feeder being formed with a plurality oforifices through which flow streams 62 of glass from the forehearth S6.As illustrated in FIGURE 2, a feeder construction o@ is disposed aboveand generally in vertical alignment with a burner or blast producingmeans Zta.

The streams from each feeder are formed into primary filaments which aredelivered into the gaseous blast beneath the particular feeder, A combmeans 6d disposed beneath each feeder is adapted to converge the rows offilaments 66 formed from the streams into a laterally aligned group.Disposed adjacent each of the comb constructions 64 is a pair of rolls68 engageable with the primary filament 66 arranged to engage theprimary lilaments 66 to attenuate the streams to filaments or rods andcontinuously advance the primary filaments through a guide means 7@arranged to direct the advancing filaments into the gaseous blastprojected from the adjacent burner 26 or other blast producing means.

The heat of the intensely hot burned gases of the blasts softens theglass of the primary filaments and the velocity of the gases of theblasts attenuates the softened glass to fine fibers.

Disposed lengthwise of the chamber l!) is a foraiminous or reticulatedconveyor 74 of the endless belt type, the upper flight 76 of the belt 7dbeing supported by rollers 77 and 7S, one of which is driven by means(not shown) to continuously advance the upper flight 76 of the conveyorin a right-hand direction as viewed in FlGURE l and lengthwise of thechamber lll in the direction of movement of the blasts. idler or guiderolls 80 engage the conveyor in a conventional manner for properlytensioning the conveyor.

As illustrated in FIGURE l, the fibers 32 attenuated by and entrained inthe gases of the blasts are continu` ously collected out of the blastonto the upper flight 76 of the conveyor. Disposed beneath the upperflight 76 of the conveyor is a walled receptacle 2a which provides achamber S6 connected by means of a duct 8S with a suction blower to setup or establish reduced or subatmospheric pressure in the chamber 86whereby a substantial amount of the gases of the blasts are withdrawninto the chamber ilo and the fibers S2 ltered out of the blast upon theforaminous or reticulated conveyor 7d.

Applicators gli, @Il and 92, as shown in llGURE l, are arranged todeliver a spray of binder, adhesive or other fiber coating material ontothe nascent fibers while the same are entrained in the gases of theblasts. rlhe groups of applicators 9i? and @l are spaced transversely asshown in FIGURE 2 and. are supported by manifolds 93 and 94 connectedwith a fitting 95 joined with a pipe 96 which is connected with supplyof binder or other liber coating material.

The applicators 92 are connected with a manifold 97 also connected witha supply of binder or other fiber coating material. The binder,preferably in liquid form or contained in a liquid vehicle is deliveredunder pressure from the applicators 9b, 9i and QZ in order to promoteeffective distribution of the binder or coating material onto the newlyformed fibers while in flight.

rhe burners 2b are of comparatively large size and as shown in FGURE 2,are of a dimension whereby the composite blast made up of the individualblasts from each of the burners is of a width substantially equal to thewidth of the conveyor whereby a mat of fibers is formed of a widthsubstantially equal to the width of the composite blast. The formed matmay be four feet or more in width.

it has been found that by employing a fiber-forming and collectingchamber of a width substantially greater than the transverse dimensionor width of the movable conveyor 7d that a fibrous mat of improvedquality and of more uniform thickness may be formed. As shown in FIGURE2, the side walls 1d and i6 of the chamber are spaced substantialdistances from the edges of the conveyor flight 76. The regions of thefloor i8 of the chamber provide lengthwise ledges 75 upon which fugitivefibers that escape the influence of the suction chamber Se collect inthe aisles at each side of the conveyor.

lt is found that by providing substantial distance beyond the transverseedges of the chamber that the amount of stray fibers deposited upon thefloor of the surface is greatly reduced over prior methods wherein theside walls y of the chamber were close to the edges of the conveyor.Some of the coated fibers cling or adhere to the side walls formingclumps and when the clumps fall from the wall surfaces, they collect onthe ledges 75 and do not impair or affect the formation of the mat onthe conveyor.

lt is well known that a high velocity blast for fiberattenuatingpurposes must have access to an air stream, the movement of which isinduced or influenced by the moving gases of the blasts. vention theadmission of air to the blasts is restricted and controlled whereby theattenuating efficiency and fiber yield is greatly improved. Positionedwithin the fiberforming and collecting chamber 10 is an air streamconveying and cont-rol duct means 98. ln the embodiment illustrated, theair duct means 93 is inclusive of a plenum portion 99 extendingtransversely of the chamber ll) and beneath the ceiling l2 of thechamber as shown in FIG- URE 2.

The plenum chamber is provided with two tubular portions ltil and M2positioned at each side of the forehearth 56 having air entrances orinlets ltlfl to admit atmospheric air into the air duct means.

Depending from the plenum portion 99 is an adjustable air conveying ductmeans. In the embodiment illustrated, the duct means includessubstantially rectangular hollow duct sections 106, lill@ and lill. Thesections M8 and lill are preferably arranged in telescoping relation andare adjustable relative to the plenum portion 99.

As shown in FlGURE l, the lowermost duct section il() is fashioned withan angular edge region i12 which is substantially at a 45 angle withrespect to a vertical plane. The region of the duct lill adjacent theangular edges 3112 provides the air outlet whereby air is admitted ordelivered to the blast under the influence of the induction actionestablished by the velocity of the gases of the blasts and the reducedpressure or suction provided in the chamber The outlet section lf2 .ofthe duct means is preferably formed with transversely extending spacedbattles 1114i and lid which define individual air cells or ducts 118,120 and 122 so as to facilitate or provide for improved distribution ofthe air above and adjacent and along the blasts. Means is provided foradjusting or changing the position of the sections ltl and lli) toregulate or control the relative position of the outlet of the ductmeans with respect to the blast 2S.

As shown in FlGURE 2, depending end portions H6 and 128 of the plenumchamber construction provide supports for brackets l2@ and i3@ welded orotherwise secured to the depending portions M6 and 123 respectively.

The upper portions of the brackets 129 and 130 are provided with boresaccommodating a transversely extending shaft 32 which is rotatablerelative to the supports. Fixedly secured to the shaft i312 are bevelgears l34 and 135 which are enmeshed respectively with bevel gears 136and 2137.

The gear i3d is fixed to a shaft i3d provided with a threaded regionwhich is threaded into a nut 139 secured to a bracket E146, the latterbeing fastened in a suitable manner to the end wall of the duct sectionlill. The gear in the arrangement of the ini 137 is fixedly secured to ashaft 144 which is rotatable in the support 130 and is provided with athreaded region which is threaded into a nut 145 secured to a bracket146, the latter being fastened to the opposite end of the duct section110. The shaft 132 is provided with a manipulating hand wheel 148 asshown in FIGURE 2 for rotating the shaft 132 and thereby adjust the ductsections 108 and 110 in vertical directions through the medium of thegearing and shaft arrangement.

The operation of the apparatus of the invention in carrying out themethod of forming fibers is as follows: The heat-softenable mineralmaterial such as glass batch, Vis introduced into the melting andrefining furnace 38 from the supply hopper 40 by the batch feeding means42. The motor 44, or other means for actuating the batch feeder, may becontrolled by conventional methods to maintain a proper supply yofmolten glass in the forehearth 56. The molten refined glass from thefurnace 38 flows through the feed channel 54, thence transverselythrough the forehearth section 56.

Streams of glass 62 ow through the orifices in the feeders 60. Theprimary filaments 66, formed from the streams 62, are directed throughthe comb means 64 and engaged by attenuating rolls 68 which continuouslyattenuate the streams to primary filaments 66. The primary filaments areadvanced by the attenuating or feed rolls 68 through the guide means 70and are continuously delivered into blasts emanating from the blastproducing means 26. The combustible mixtures supplied to the combustionchambers 27 of the burners 26 are burned within the chambers and theintensely hot burned gases delivered through the elongated restrictedorifices 34 as high velocity gaseous blasts 28.

The heat of the gases of the blasts softens the advancing extremities`of the primary filaments 66 and the velocity of the gases attenuatesthe softened glass to fine fibers 82 which are entrained in and carriedalong by the blasts.

Binder or other fiber coating material may be delivered yonto thenascent fibers from the applicators 90, 91 and 92 -while the fibers arein flight.

The endless conveyor 74 is continuously actuated or Adriven in adirection to advance the upper ight 76 in the direction of movement ofthe gases of the blasts at a speed dependent upon the thickness desiredfor the mat. The upper flight is preferably inclined upwardly tofacilitate ydeposition of the fibers upon the reticulated conveyor.

Suction or reduced pressure established in the chamber 86 by a suctionblower (not shown) is effective to convey -away the spent gases of theblasts, the fibers being filtered out of the gases on the conveyor.

The transverse wall or bafiie 22 is formed with a narrow opening toadmit the passage of the gases of the -blasts and hence very littleblast-induced air is admitted through this opening. The major amount orquantity of induced air admitted to the blast is by way of the air ductsystem 98. The air fiows through the inlets 104 to `the plenum 99 thencedownwardly through the duct sections y108 and 110 and is deliveredthrough the several outlets 118, 120 and 122 formed by the partitions orbafiies 114 and 116. This arrangement provides for a control of the airadmitted to the blasts and restricts the air to a region adjacent theblast, This control arrangement .greatly reduces or substantiallyeliminates the formation of turbulence in other regions of the fibercollecting chamber or hood 10. The arrangement of providing substantialspaces between the transverse edges of the conveyor flight 76 and thewalls 14 and 16 of the chamber serves to further reduce turbulence ateither side of the conveyor and minimizes the tendency of fibers to bediverted to the regions adjacent the side walls of the chamber and hencereduces the rate of accumulation of fugitive or stray fibers on thewalls 14 and 16 and in the aisles at either side of the conveyor. It isfound that through this arrangement of exercising effective control overthe blastinduced air stream that a substantial increase in the pro- 6duction of fine fibers is attained. Furthermore the mat of collectedfibers is more uniform and clumps of fibers and streamers -in the matare greatly reduced.

The outlet or region of delivery of controlled air from the air ductsystem to the blast may be in the proximity of the source of the blastas illustrated in FIGURE 1, or the controlled air may be deliveredfurther along the blast depending upon the characteristics of the blastand other operating conditions.

The provision of the increased width of the fiber collecting chamber andthe controlled air stream result in a substantial rate of reduction inthe accumulation of fibers on the side walls 14 and 16 and hence theoperation may be carried on for greater periods of time before itbecomes necessary to purge or clean the side walls and aisles of wastefibers. In installations where the side walls are disposed close to theconveyor, clumps or streamers of accumulated binder-coated fibers on theside walls period ically fall onto the collected mass of fibers andresult in a mat of non-uniform thickness or character. With the wallsspaced substantially transversely from the conveyor, any clumps of bersfreed from the side walls fall into the aisles at each side of theconveyor and do not affect the mat collected upon the conveyor.

While the arrangement illustrated in the drawing employs a meltingfurnace as a supply -of heat-softened glass *for forming the primaryfilaments 66, it is to be understood that independent glass feeders maybe disposed at the position occupied by the forehearth 56 and marbles ofpre-refined glass introduced into the feeders and electrically heated toa flowable condition, the glass flowing through orifices in the iioorsof the feeders and primary filaments formed from the streams in the samemanner as described herein.

It is apparent that, within the scope of the invention, modificationsand different arrangements may be made other than as herein disclosed,and the present disclosure is illustrative merely, the inventioncomprehending all variations thereof.

We claim:

1. Apparatus of the character disclosed, in combination, a walledchamber, means arranged to project a high velocity gaseous blastlengthwise of said chamber, means for delivering bodies of fiber-formingmineral material into the blast whereby the material of the bodies isattenuated by the blast to fine fibers, means in said chamber disposedto impede the admission of air to the blast at a region adjacent andforwardly of the blast projecting means, and an air conveying meanshaving an entrance exterior of the chamber and an outlet within thechamber and adjacent the blast for delivering air to said blast.

2. Apparatus of the character disclosed, in combination, an elongatedwalled chamber, means arranged to project a high velocity gaseous blastlengthwise of said chamber, means for delivering bodies of fiber-formingmineral material into the blast whereby the material of the bodies isattenuated by the blast to fine fibers, a foraminous conveyor in saidchamber arranged for movement lengthwise of the chamber in the directionof the blast upon which the bers are collected, a transverse baffledisposed adjacent the blast projecting means having an opening throughwhich the blast is projected, an air conveying duct extending into saidchamber, said air duct having an entrance exterior of the chamber and anoutlet within the chamber adjacent the blast for delivering air to theblast.

3. Apparatus of the character disclosed, in combination, an elongatedwalled chamber, a plurality of blast-projecting means arranged toproject high velocity gaseous blasts lengthwise of said chamber, meansfor delivering bodies of fiber-forming mineral material into the blastswhereby the material of the filaments is attenuated by the blast to finefibers, a foraminous conveyor in said chamber arranged for movementlengthwise of the chamber and upon which the fibers are collected, theside walls of the chamber being spaced substantial transverse distancesfrom the conveyor, a transversely arranged baiile disposed adjacent theblast projecting means, an air conveying duct having an entranceexterior of the chamber and an outlet adjacent the blasts, and means forcontrolling the position of the outlet ot the duct relative to theblasts.

4. Apparatus of the character disclosed, in combination, an elongatedwalled chamber, a plurality of blast-projecting means arranged toproject high velocity gaseous blasts lengthwise of said chamber, afeeder adapted to contain heat-softened mineral material and providedwith orice means through which llow streams ot the material, means toradvancing primary filaments formed from the streams into the blastswhereby the material of the laments is attenuated by the blasts to linefibers, a foraminous conveyor in said chamber arranged for movementlengthwise of the chamber and upon which the iibers are collected7 atransverse Wall in said chamber disposed adjacent the blast producingmeans and having a restricted opening through which the blasts areprojected, air conveying duct means extending into said chamber adjacentsaid transverse wall, said air duct having an entrace exterior of thechamber and an outlet adjacent the blasts, and partition means in saidduct means providing controlled streams of air admitted to the blasts.

5. Apparatus of the character disclosed, in combination, an elongatedwalled chamber, a plurality of blastproducing means arranged to projecthigh velocity gaseous blasts lengthwise of said chamber, receptaclemeans adapted to contain heat-softened mineral material and providedwith orifice means through which ow streams of the material, means foradvancing primary filaments formed from the streams into the blastswhereby the material of the filaments is attenuated by the blast to nefibers, a foraminous conveyor in said chamber arranged for movementlengthwise of the chamber and inclined upwardly in the direction of theblasts upon which the libers are collected, a transverse wall in saidchamber disposed adjacent the blast producingmeans and having arestricted opening through which the blasts are projected, an airconveying duct extending into said charnber adjacent said transversewall and above the paths of movement of the gases of the blasts, saidair duct having an entrance exterior of the chamber and an outletadjacent the blasts, partition means in said duct providing controlledstreams of air admitted to the blasts, and means arranged to vary theposition of the outlet of the duct relative to the blasts.

6. Apparatus of the character disclosed, in combination, an elongatedwalled chamber, a blast-projecting means arranged to project a highvelocity gaseous blast lengthwise of said chamber, means for deliveringbodies of liber-forming mineral material into the blast whereby thematerial of the bodies is attenuated by the blast to line fibers, aforaminous conveyor in said chamber arranged for movement lengthwise ofthe chamber upon which the bers are collected, a transverse wall in saidchamber disposed adjacent the blast producing means, a substantiallyvertically arrangedair conveying duct means for conveying air to theblast, the side walls of the chamber being spaced substantial distancesfrom the conveyor providing an aisle at each side of the conveyor, and acompartment arranged beneath the conveyor and adapted to be maintainedat subatmospheric pressure for conveying away the spent gases oftheblast.

7. Apparatus of the character disclosed, in combination, an elongatedwalled chamber, a plurality of blastproducing means arranged to projecthigh velocity gaseous blasts lengthwise of said chamber, feeder means.adapted to contain heat-softened mineral material and provided withorilices through which ilow streams of the F material, means foradvancing primary lilaments formed from the streams into the blastswhereby the material of the filaments is attenuated by the blasts tofine fibers, a foraminous conveyor in said chamber arranged for movementlengthwise of the chamber in the direction of the blasts upon which thefibers are collected, a baffle in said chamber disposed adjacent theblast producing means arranged to impede ilow of air to the blasts, ductmeans for conveying air to a Zone within the chamber adjacent theblasts, means for adjusting the relative position of the outlet of theduct means to modify the region of delivery of air from the duct meansto the blasts, the side walls of the chamber being spaced substantialdistances from the conveyor providing an aisle at each side of theconveyor.

S. Apparatus ot the character disclosed, in combination, an elongatedwalled chamber, a plurality of blast-producing means arrangedintransversely-aligned relation adapted to project high velocity gaseousblasts lengthwise of said chamber, feeder means adapted to containheat-softened mineral material and provided with oririces through whichiiow streams of the material, means for advancing primary filamentsformed from the streams into the blasts wherebythe material of theiilaments is attenuated by the blasts to tine fibers, a foraminousconveyor in said chamber arranged for movement lengthwise of the chamberin the direction of movement of the blasts upon which the fibers arecollected, a transverse wall in said chamber disposed adjacent the blastproducing means and having a restricted open area through which theblasts are projected, a substantially vertically arranged air conveyingduct means for conveying air to a zone adjacent the blasts, said ductmeans including a relatively movable section providing an outlet for theduct means, and means for adjusting the relative position of the outletsection oi the duct means to modify the region of delivery of air fromthe duct means to the blasts.

9. Apparatus of the character disclosed, in combination, an elongatedwalled chamber, a plurality of blastproducing means arranged to projecthigh velocity gaseous blasts lengthwise of said chamber, feeder meansadapted to contain heat-softened mineral material and provided withoritice means through which ow streams of the material, means foradvancing primary iilaments formed from the streams into the blastswhereby the material of the filaments is attenuated by the blasts tofine bers, a foraminous endless conveyor in said chamber arranged formovement lengthwise of the chamber, the upper flight of the conveyorbeing inclined upwardly in the direction of the blasts upon which thebers are collected, a transverse wall in said chamber disposed adjacentthe blast producing means and having a restricted opening through whichthe blasts are projected, a substantially vertically arranged airconveying duct means for conveying air from a region exteriorly of thechamber to a zone adjacent the blasts, said duct means having an outlet,means for controlling the relative position of the duct means to modifythe region of delivery of air from the duct to the blasts, the sidewalls of the chamber being spaced substantial distances from theconveyor providing an aisle at each side of the conveyor, and acompartment arranged beneath the upper flight of the conveyor andadapted to be maintained at subatmospheric pressure for conveying awaythe spent gases of the blasts.

itl. A method of controlling the liber-attenuating er1- vironment of ahigh temperature, high velocity gaseous blast arranged to form `bersfrom heat-softenable mineral material including projecting a blast ofhightemperature, high velocity gases into a chamber, impeding theadmission of air to the blast at a region adjacent and forwardly of thesource of the blast, and flowing air into the chamber from a regionexteriorly of the chamber in a coniined path normal to the direction ofilow of the gases of the blast and delivering said air to a regionadjacent the blast whereby the direction of movement of said air isabruptly diverted by the velocity of the gases of the blast for movementalong the blast whereby to reduce turbulence in the chamber.

(References on following page) References Cited by the Examiner UNITEDSTATES PATENTS Stalego 657 Stalego 65--16 Schwartz 117-126 Labino 65-7Drummond 65-3 Toulmin 65-11 Drummond 65-4 Karlovitz et a1 65--5Karlovitz 65-13 Roberson 65-5 DONALL H. SYLVESTER, Primary Examiner.

MICHAEL V. BRINDISI, WILLIAM B. KNIGHT,

Examiners.

1. APPARATUS OF THE CHARACTER DISCLOSED, IN COMBINATION, A WALLEDCHAMBER, MEANS ARRANGED TO PROJECT A HIGH VELOCITY GASEOUS BLASTLENGTHWISE OF SAID CHAMBER, MEANS FOR DELIVERING BODIES OF FIBER-FORMINGMINERAL MATERIAL INTO THE BLAST WHEREBY THE MATERIAL OF THE BODIES ISATTENUATED BY THE BLAST TO FINE FIBERS, MEANS IN SAID CHAMBER DISPOSEDTO IMPEDE THE ADMISSION OF AIR TO THE BLAST AT A REGION ADJACENT ANDFORWARDLY OF THE BLAST PROJECTING MEANS, AND AN AIR CONVEYING MEANSHAVING AN ENTRANCE EXTERIOR OF THE CHAMBER AND AN OUTLET WITHIN THECHABMER AND ADJACENT THE BLAST FOR DELIVERING AIR TO SAID BLAST.
 10. AMETHOD OF CONTROLLING THE FIBER-ATTENUATING ENVIRONMENT OF A HIGHTEMPERATURE, HIGH VELOCITY GASEOUS BLAST ARRANGED TO FORM FIBERS FROMHEAT-SOFTENABLE MINERAL MATERIAL INCLUDING PROJECTING A BLAST OF HIGHTEM-